Niall Ferguson-- reduce the national debt

According to the news, that I can know, if UK wants to reduce the national debt, the government needs to increase the tax and cut the government spending. therefore the government will get more income which may help the treasury to increase their financial assets. Then the national debts will decrease.
advantages:
For a long term, a low national debts is good for the development of domestic economic. Because less debts will reduce the pressure of the government, they do not need think about how to return the debts anymore. Then they can pay more attention on their own economy. Also reduce on national debts classify the economic of this country is not bad, it may growth which is better than before. Also reduce the debts may save more money, because the government may not pay the interest rate, and nowadays, the exchange of English pounds is depreciating, which means they will pay more money to the country that lent money to UK.

disadvantages:
In another hand, reduce the national debts is not a good idea, because if some crisis suddenly happened, for example global recession, the government can not deal with it on time, cause they do not have enough money. also they can not spend more to encourage their domestic business,such as invest some small firm, help some company which face to bankrupt and so on.
For instance, in 2012, UK will hold the Olympic games, for the government this is a quite big leakage, so they need borrow money from other countries.
But for the content above depends on the different countries. some rich countries are not really a debtor, they might be a creditor. otherwise for some poor countries, their treasury may become empty, they need help from other countries. Also it depends on different situation of different time. For example, nowadays, all the world face to global recession, America which is the richest country,but they borrow more than 10 billion dollor s from China ti deal with the problem.
conclusion:

At the end, I think reduce the debt or not depends on the different situation of different countries, because for different time reduce the national debts will bring the different effects for them, even though the good or bad effects.